


Works Every Time

by MeGaLoTrash



Category: Undertale (Video Game)
Genre: Anal Fingering, Anal Sex, Ass Play, Basically everyone X uf! Sans, Cherryberry - Freeform, Dry Humping, Ectobiology, Fellcest - Freeform, Fight Sex, Frottage, Full ectobody, M/M, Multiple Pairings, Oral Sex, PWP, Pining, Rimming, Sexual Tension, Smoking, Underfell Papyrus, Underfell Sans, Underswap Papyrus, Underswap Sans, Undertale Papyrus (mention), Undertale Sans, Virgin Honey, ass worship, honeymustard - Freeform, kustard - Freeform, mild drug use
Language: English
Status: Completed
Published: 2018-08-01
Updated: 2018-08-01
Packaged: 2019-06-20 07:47:56
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,426
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/15529536
Author URL: https://archiveofourown.org/users/MeGaLoTrash/pseuds/MeGaLoTrash
Summary: Ok so this is a purethirst™ pwp mess with Red x everyone (ships in the tags) where they all just love his big butt. No joke. BlameTHIS THING. This is what insanity looks like friends.





	Works Every Time

Red turned his body from side to side as watched his reflection in the full length mirror. He was in his brother’s room but thankfully Edge was out for the morning. Leaving him to observe himself objectively and without any outside influences. It wasn’t that Edge would protest to what Sans was doing, quite the opposite actually, but he would scold him for being so indecisive about choosing a pair of shorts to wear. Either that or the shorts would have their desired effect and Red would find himself being coerced into bed by the one skeleton he could never resist. While Red wouldn’t usually complain about the attention from his brother, he had another monster in mind for today. They had a mutually beneficial open relationship, nothing underhanded there, but Red was planning on some interesting tactics to get exactly what he wanted.

It wasn’t anything too bad, he was just planning on using his best _ass_ ests to their full potential if he wanted to pull this off. 

In short, Red was able to form the juiciest ass in the entire multiverse. It was large, just like the rest of him, and he’d spent a lot of time figuring out how to make his magic form the perfect globes he currently sported but holy hell was it worth it. It had all came about when he was jacking off to some of the human trash he’d found in the dump one day. He’d picked up a speciality magazine, _Big booty bitches 5_ to be exact, and noticed how members of all the sexes were fawning over the huge butts on every page. Red wanted in on that. He wasn’t usually one to care about his appearance but he was aware that his magic did gravitate to that area. With a bit of concentration and manipulation of his form while keeping a hand moving on his cock he moulded an ass worthy of being on the front page of the next issue. Not only did it look good enough for him to get off to his _fucking reflection_ but it also jiggled real nice when he walked. 

He just needed someone to show off too. 

This was all before he had found out about the alternative universes. Before the nicknames when they were just another Sans and Papyrus and Red had only had eyes for his brother. They had always been close, closer than brothers had any right to be, but bar a few nights of drunkenly fumbling with each other they hadn’t exactly sealed the deal. Red knew Edge wanted him no matter how hard he tried to hide it. Their unique mix of fighting and flirting had been getting more intense recently and Red was tired of beating his junk raw as he strained to hear his brother through their bedroom wall. Things had to change and he had an idea that was just crazy enough to work.

Since they lived together walking in on each other in various states of undress was just part of the package deal. Red noticed he happened to walk in on Edge semi-nude after they had a big fight. _a lot_. Like his brother was just tempting him to give in to the tension between him and take what he wanted. The problem was that they were both as stubborn as each other and Red caving first would mean that Edge would always have the upper hand. Red had no problem with his brother taking charge on occasion, in fact he couldn’t think of anything hotter than Edge pinning him down and riding him, but he wasn’t gonna give him the opportunity to have a complete monopoly over him. _where would be the fun in that?_ Their relationship might be messed up beyond reason, but holy fuck did it make him feel alive. 

Red might have been above making the first real move he had no problems with turning up the heat on the ‘accidental nudity’. He planned the best way to show off his new magic for a few days before realising that simplicity was the key. One day he went down to breakfast and ‘forgot’ to put on anything to cover his bottom half. No shorts or boxers or anything, just the same tank top he always wore to bed that only just managed to cover his dick and nothing else. He’d done this before, usually when raiding the cupboards at 3am after a nightmare, but never with his ecto body formed from the ribs downwards. He tried to make it seem as casual as possible, like he really had been careless enough to forget, but he couldn’t resist pulling the tank down at the front so his whole ass would be on display. 

Luckily for him, Edge was far too distracted to notice the finer details. He was in the kitchen when Red came down and would have fired off his usual orders if seeing Red hadn’t made him freeze. Red played it cool while his brother’s skull flushed a vibrant scarlet, pretending not to notice and yawning loudly for good measure. It was so tempting to check behind him when he went to grab some chisps out of the fridge but he stuck to his plan. No matter how much he wanted to see what face his brother was making upon getting a proper look at his ass. The little squeak Edge made when he turned back around and realised Red had caught him staring was enough to fuel his fantasies for days. 

Red had done his bottomless trick for the next week, each day daring to stand there a little longer while he picked up his breakfast. He ended up getting restless though. Edge was practically drooling over him, even going so far as to sit on the counter and watch him with no regard of being caught, but he hadn’t made a move yet. The tension was so high that they couldn’t be within ten feet of each other without it ending in a fight, verbal or otherwise. Red had almost snapped when he and Edge were locked together, both pulling at the front of each other’s clothes as they traded scathing insults. The tension was tangible, enough to cut with a knife. Red would have sworn he even saw actual sparks of magic flying between them. 

It would have been so easy for Red to overpower his brother, tear off his pants, and fill him up with the magic he couldn’t keep his eyes off in the mornings. But he held back by the skin of his teeth, teleporting away as soon as they were disconnected to deal with the pulsing cock in his pants. He jerked off to the idea of finally getting Edge to snap and his lust clouded mind gave him the idea he’d been searching for. When he made his bottomless trip to the kitchen the next day he didn’t even bother to hide the way his cock was already at half mast. He waited to have Edge’s full attention before he bent over in front of him in the guise of getting something on the lowest shelf. He didn’t make a show to actually grab anything though, far too distracted by the image of Edge seeing everything he had to offer. 

Red was rock hard when he felt his brother finally slide up behind him, the heavy breathing and shaky hands on his flesh telling him all he needed to know. Edge was out of it; transfixed with his magic and begging, _actually fucking begging_ , for Red to let him touch him. Red had told him to do whatever he wanted but his smug chuckle had died on his tongue when he felt Edge drop to his knees. He moaned feeling his brother’s gloved claws pulling and scratching at his pseudo-flesh first but almost choked when he felt a wet tongue joining in the exploration. He had lived with Edge all his life but never in a million years thought that his brother would be such a kinky fuck from the get-go. It felt like all of his Giftmases had come at once. 

Edge didn’t leave an inch of flesh untouched by either his hands or his tongue before he shoved his head between Red’s cheeks and started to eat him out. Red had to grip the base of his cock to keep himself from busting a nut too soon but frustration over being edged eventually drove him to flip their positions so he could fuck his brother into the countertop. Hearing the slap of his formed flesh against his brothers with every thrust was like a chorus of applause for them finally doing the deed. Edge dug his heels into Red’s ass for leverage, something that was bound to leave marks he wouldn’t want to forget any time soon. Not to mention his brother’s screams for more, which he gave him until his legs turned to jelly. Then Edge did something straight out of his fantasies: rode him on the kitchen floor until he milked him dry. 

This was the start of a strange but fulfilling relationship between them. Red would have died a happy man with his brother as his only bedmate, Edge was a perfect match both in the bedroom and relationship wise, but the universe had other plans. Thankfully they both had similar ideas about their newfound alternates being fair game.

Honey was next. Red knew as soon as he laid eyes on the smug, chain-smoking, flirty asshole that he had to have him. Everything about Honey was so alluring to him, the body of his brother with a personality more matched to his. The adorable laugh he had coupled with the way he had the cutest little flecks of orange magic on his cheekbones that lit up when he blushed made Red weak to his charms. He had a hunch that even the Papyruses from the sweeter universes were kinky fucks if their buttons were pressed right, and Honey gave off the vibe that he’d been around the block a few times. 

Which of course meant Red put his foot in his mouth when he found out Honey was a complete virgin. 

He might have been inexperienced but _fuck_ was Honey eager to learn. Red decided that there was no point trying to fix what wasn’t broken and tried to pull the same trick he had used to entice Edge. He waited until he was alone with Honey, an afternoon away hid away from their brothers while smoking something they shouldn’t have before he found an opportunity to rid himself of his shorts. His idea had been to try and laugh it off as a side effect if Honey hadn’t been interested, but he hadn’t anticipated Honey almost dislocating his jaw in shock. Red had tried cocky confidence at first before realising there was a reason Honey had locked up. The other skeleton had confessed that he was a virgin while covering his face and Red had apologised and scrambled to put his shorts back on. 

He didn’t get far before Honey had asked if he could try something in a voice barely above a whisper. Red told him he could do whatever he wanted and had groaned appreciatively when Honey turned him around so he could grab his ass. It felt nice to lean back into Honey’s slightly taller frame as he let him explore at his own pace. Red was caught off guard when Honey gave him a reach around on his own accord, even if he had buried his face in the crook of Red’s neck to hide his embarrassment. Honey worked one hand up and down Red’s shaft with minimal guidance, while his other hand grabbed one of Red’s cheeks. He got Red off in a matter of minutes with the joint attention and Red returned the favour by spending the rest of the afternoon eating his sweet pussy. 

He had tried not to overwhelm the poor thing for his first time, but it was Honey’s fault for making the most delicious sounds when he came. Which Red made sure to happen at least five times. 

Red realised he had a niche to exploit but his next target was laughably easy in comparison. Out of everyone Sans, the one that got to keep his name since they found the other universes first, was the most similar to him in their little group. Red didn’t devise a plan, just turned up in his kitchen one day with the same bottomless outfit. Sans had laughed at his boldness, shot him a wink and dropped-trou to join him. They went about getting some snacks together comfortable enough to laugh and playfully jibe each other while checking each other out. It was the perfect mix of hilarious and really fucking hot which only escalated when a screeching Papyrus demanded they go back to Sans’s room to make themselves decent. 

Sans was all smiles and goofy laughter until the door shut behind them. Then he was all over Red like a bad rash. Red was just as keen to get his hands on Sans’s ass as he was to get to his, having got a decent look at the second best ass in the multiverse when they were messing about in the kitchen. They kissed passionately while grabbing each other close and rutting together on the spot in the most physical exercise either of them had got in months. After they both came hard from the dry humping they moved to Sans’s bed and spent a lazy afternoon with their mouths between each other’s legs. Red finally got to appreciate how good being on the receiving end of having an ass in your face could be and he made sure he left Sans with exactly 0 complaints. In fact, he’d given his double some tips about how some of the Papyruses had a bit of a thing for ass worship after being with him. He had to look after his own after all. 

Which was why he was confused about his current target giving him so much trouble. 

Blue was an odd one to figure out. He was more similar to Edge and especially Papyrus, the latter of which Red had written off as an unobtainable angel, but he was a Sans. There was just _something_ under his happy-go-lucky exterior that lit a fire in Red’s soul. Honey wasn’t any help. He and Blue had only just started sleeping together once they realised that their mutual attraction wasn’t frowned upon in their little group and any mention of Blue would turn him into a blushing schoolgirl. Red had almost given up hope when Edge let slip an interesting interaction in their pillow talk.

One of the great things about sleeping with their alternates was getting to share it with each other. It both brought them closer and lead to some incredible sessions together, but that was beside the point. Edge mentioned he’d caught Blue checking him out when they were training together and hadn’t even tried to hide it. Blue was a known flirt but it always came across as playful rather than serious. Edge had described him as looking fucking _hungry_. Red had thanked his brother for the information by making him cum on his tongue, all the while knowing that he and Edge would be in competition to see who could crack Blue first. 

So Red started to hang out with Blue at every opportunity he got. He knew that his usual tactic of parading his naked ass in front of Blue wasn’t going to work straight away but he was willing to wait to see that flicker of something more himself. Only it never came. He and Blue were flirting like crazy but Blue never once let his cheerful demeanor slip. Red thought about giving up the chase but then he was struck with a compromise. He might not be able to get away with walking around naked but there were certain things he could wear that would make it impossible for Blue to keep his eyes off him. 

Which was why he was picking out shorts today- _oh shit_

Red cursed himself and checked the time. He had spent so long lost in his thoughts that it was nearly time for him to meet Blue in his house. Not only that but his graphic recalling of recent events had given him a semi that wouldn’t go away no matter how many times he tried to push it down. He was worried that he was going to miss his chance but then caught a look at himself in the mirror. The tiny tight black shorts were not only clinging to every curve of his ass but now the front of the shorts looked just as tight. Red gave himself one last look over before he left for Blue’s universe, unable to hide the lecherous grin forming on his face. 

If Blue wasn’t a big ass fan then maybe seeing the outline of his cock would do the trick instead. 

“Hello Red!” Blue was at the door before Red had even finished knocking. 

He didn’t mind though. He came prepared to stare at Blue’s face to catch the moment he realised what Red was wearing. But it never came, he just stood there with the same happy expression as he waited for Red to say something. He wasn’t even deterred when Red didn’t reply, stepping out of the way to let his double inside without missing a beat. 

“Come In, I’ve Just Made Some Cookies For Honey But I’m Sure He Won’t Mind If You Have Some.” 

Red had hoped that Blue might have just missed what he was wearing in the front on view but his cheerful double didn’t even falter when Red briefly turned his back to him. Blue was either far too polite to point it out, oblivious, or both. 

“erm, notice anythin’ different?” Red eventually asked, because like hell was he gonna let all his careful planning go to waste. 

“Sure Do! That’s Not The Outfit You Usually Wear, Though I’m Not Sure What The Occasion Is-” Blue’s eyes turned into stars as he clapped his hands excitedly. “Oh Gosh Red, Is This Your Workout Outfit? That Is Something Very Different!”

“what- no! it’s just hot today, don’t ya think?” Red replied quickly, trying not to let his skull flush too quickly from the embarrassment of Blue being so direct. _and not in the good way_ It wasn’t a nice feeling to know his obvious hints were going over Blue’s head but he had to hold it together since he still wanted to spend time with his double regardless. “-and y’know, need t’ do laundry and shit” he added, hoping that one of the excuses would stick. 

“Oh Ok, If You Say So!” Blue replied with an even wider smile. There was a moment, a millisecond where his eyes flicked down towards Red’s crotch before he asked-“Cookies?” 

Red wasn’t sure if he was clutching at straws or if he was seeing things that he _wanted_ to be there but that tiny slip had renewed his hope. He followed Blue into the kitchen, his eyes unable to keep from wandering over Blue’s own form, and took a cookie when he was offered. They made idle chit-chat and he tried not to make it awkward with his cock still half hard in his pants. He finished the cookie and Blue had just said he could have as many as he wanted when he had another one of his bright ideas. He couldn’t believe he was gonna try the oldest trick in the fucking book...but if it worked then he didn’t care how lame it was. 

Red walked over to the plate of cookies, picked one up, and then ‘accidentally’ dropped one on the floor. He knew he would have to act fast or Blue would be offering to pick it up for him so with speed he didn’t know he had he bent over to retrieve the fallen snack. He not only felt the tiny shorts rise up around his ass but also felt them tighten almost painfully around his hardening cock. He really needed to consider just how hot his exhibitionist streak got him at a later date, but now was not the time. 

Red heard Blue gasp quietly before his dreams came true and he picked up the sound footsteps approaching him from behind. 

_heh, works every time._

“Need A Little Hand?” Blue moved faster than he expected, bending over Red’s body to whisper low against the side of his skull “-Or Maybe You’d Like Something Else?”

There was no question as to what Blue was alluding to when Red felt something hot and heavy slide in between his ass cheeks. Blue was fucking hung, and he was rock hard, something Red couldn’t believe he hadn’t noticed earlier. He didn’t have a chance to dwell on anything though when he felt Blue grabbing hold of his ass on both sides so that he could thrust his cock hard against him. 

“fuck, blue!”

“Language!” Blue paused his thrusting momentarily to slap one of Red’s ass cheeks hard enough to make him choke on any response. “First You Show Up In Next To Nothing-” Blue replaced the hand on his ass and made Red moan with another hard thrust “-Then You Present Yourself Like A Bitch In Heat-” Blue was relentless, pulling Red closer to him with every pass “And Now The Potty Mouth? Honestly Red You Need To Learn A Little More-” Blue groaned himself when the head of his cock caught on Red’s hole through their clothing “-Self Control.” 

Blue pulled away momentarily, giving Red respite enough to stand up and brace himself against the wall before the sound of a zipper made him shudder. Blue came back into position, the change of angle and paper-thin barrier of his shorts and Blue’s freed cock meaning that Red could feel _everything_. Never in a million years would he have expected Blue to be the one to take charge. But now he couldn’t think of anything he wanted more than to have Blue fuck him with his huge dick until he passed out.

“blue, please, that feels so fu-i mean so fricking good,” Red groaned as he shivered against his double, not caring about how fast he was turning into Blue’s bitch. 

“Well, When You Ask Like That.” 

_not when it got him what he wanted._

Blue tried to remove the shorts properly but when they got stuck he tore them to shreds. Red was pushed to the wall roughly and held there while Blue sank to his knees. His hands might have been smaller than Honey’s and his tongue flatter than Edge’s but he turned Red into a blubbering wrecked as he prepared his hole with both. He even rivalled Sans for how thoroughly he worked him up, having Red begging incoherently by the time he was done. In a surprising move he turned Red to face him when he stood back up before picking him up under his ass and sinking in with one hard thrust. 

Red arched his spine off the wall with a loud scream as Blue started to move inside him. All of Red’s anxieties about being the bottom were dulled when he realised just how well Blue had taken care of him. The ‘sweet’ skeleton definitely had more experience than he was letting on, that was for sure. Red was able to relax into it more and notice the little things like the way Blue’s hands were digging into his flesh more with each thrust and the way he hadn’t been able to take his eyes off Red’s face. Blue’s eyes were hypnotising, finally showing Red that hidden desire that he’d only caught glimpses of in the past. He found himself hoping that this wasn’t going to be a one-off between them more than once. 

With a pace this fast and hard it was no wonder that both of them were already ready to cum. Red’s neglected cock hung heavy between them but a change of angle on Blue’s part squished it between them enough that he was able to gain some much-needed friction. That and hearing Blue start to fall apart and moan his name was what did it for Red. He came with a drawn-out moan, spilling his sticky load in between them and yelping when Blue’s thrusts started to stutter. He gripped Red as hard as he could and hilted inside him, filling his ass with magic as he groaned loudly. When blue eventually pulled out Red felt some of it drip out of him and smear over his cheeks as a breathless Blue lead them towards the couch. 

“God Red That Was Incredible.” Blue sighed when he collapsed next to him after making sure he’d grabbed an old blanket so they didn’t make a mess. “Why’d It Take You So Long To Turn Up Like This Though, I’ve Been Waiting For You For Weeks.” 

“what?” Red couldn’t even try to hide his surprise at such a straight-talking side of his double. “if ya knew about me, why didn’t ya say anythin’ sooner.”

“Well That’s My Thing-” Blue explained while he crawled closer to Red, his hands already starting to roam over Red’s naked bottom half.“I Don’t Like To Push Anyone So I Wait For Them To Make A Move, I Like To Find Out What They Want- You Know, Sex-Wise- And Then Scratch That Itch As Best I Can.” 

Blue laughed and leaned in to kiss Red when he just stared dumbfounded at such a change of character. Red’s mouth responded automatically to the kiss, doing what came naturally while his mind tried to catch up. 

“I Just Want Our First Time To Be Mind Blowing You Know?” Blue added with a when he pulled away, letting his hands roam back to Red’s ass which he kneaded affectionately. “It Was Today, Amazing I Mean, I Already Want More.”

Red was still completely out of sorts though, unable or unwilling to believe he’d been played by Blue of all monsters. “but why’d you do if you coulda had me weeks ago.” 

“If I’m Being Completely Honest, The Game Is A Huge Turn On For Me-” Blue winked as he leaned in close enough to make their rapidly hardening cocks touch. “-And It Works Every Time.”


End file.
